Method and apparatus for a reflective mask that is inspected at a first wavelength and exposed during semiconductor manufacturing at a second wavelength

ABSTRACT

A reflective mask is described having non-reflective and reflective regions, where the reflective regions are reflective of a first light that has an inspection wavelength and are reflective of a second light that has a semiconductor processing exposure wavelength. The non-reflective regions are less reflective of the first light and the second light than the reflective regions in order to create: 1) a first image with a contrast greater than 0.210 and that is formed by reflecting the first light off of the reflective mask; and 2) a second image with a contrast greater than 0.750 and that is formed by reflecting the second light off of the reflective mask.

FIELD OF THE INVENTION

The field of invention relates to semiconductor lithography in generaland mask manufacturing techniques that allow for DUV based inspection ofEUV reflective masks more specifically.

BACKGROUND

Masks are used in semiconductor processing to properly form regions oflight that are subsequently directed onto a semiconductor substrate.Depending on the type of resist (e.g., positive or negative) that iscoated upon the substrate, the regions of light formed by the maskcorrespond to either the specific structures formed on the surface ofthe semiconductor substrate (e.g., gate electrodes, source/drainelectrodes, vias and interconnect lines, among others) or the spacesbetween these structures.

Masks are patterned in a manner that corresponds to the structuresformed on the substrate. A mask essentially affects the optical pathbetween an exposure light source and the semiconductor substrate. Thepatterns on the mask prevent various portions of the exposure light fromreaching the semiconductor substrate. As such, the mask is patternedwith opaque as well as non-opaque regions.

The opaque regions prevent exposure light from reaching thesemiconductor substrate. The non-opaque regions allow exposure light toreach the semiconductor substrate. The specific patterning of the mask'snon-opaque regions corresponds to the shape of those regions of lightthat are subsequently directed onto the semiconductor substrate.Typically, each layer in a semiconductor device has its owncorresponding mask that is used to form the specific structures at eachlayer according to the semiconductor device's particular design.

Traditionally, transmission masks have been used for Deep Ultra Violet(DUV) lithography associated with semiconductor processing. Transmissionmasks are essentially inserted into the optical path between theexposure light source and the semiconductor substrate. A transmissionmask 100 is shown in FIG. 1a. With transmission masks, the opaqueregions 101 absorb and/or reflect exposure light while the non-opaqueregions 102 are transparent to the exposure light. The light 103 passingthrough the non-opaque regions 102 is then directed to the semiconductorsubstrate surface.

As smaller and smaller device sizes are continually being formed withinthe semiconductor industry, the wavelength of the exposure light sourcecontinues to be reduced. As Extreme Ultra Violet (EUV) technologyemerges, reflection rather than transmission masks are being developed.Reflection masks are positioned along the optical path between theexposure light source and the semiconductor substrate. A reflection mask104 is shown in FIG. 1b. With reflection masks, the opaque regions 105absorb exposure light while the non-opaque regions 106 reflect exposurelight. Thus, for reflective masks, non-opaque regions correspond toreflective regions and opaque regions correspond to non-reflectiveregions. The light I_(reflective) reflecting off of the reflectiveregions 106 is then directed to the semiconductor surface.

During the mask manufacturing process, defects in the mask patterningare searched for, found and corrected. Defects may be searched for atmultiple instances during the mask manufacturing process. For example,before and after a buffer layer 107 (of FIG. 1b) is etched. A problemwith the manufacturing of masks for EUV applications is that the toolsused for the searching of patterning defects may not operate within theEUV spectrum (which, for purposes of this application, corresponds tolight at wavelengths within 10-100 nm) but rather, the DUV spectrum(which, for purposes of this application, corresponds to light atwavelengths within 100-300 nm).

Since the mask is designed to affect EUV light, the optical propertiesof the non-reflective and reflective regions in the EUV spectra may bedissimilar from their optical properties in the DUV spectra. This mayresult in difficulties when searching for defects. Principally, if themask does not exhibit a suitable difference between the reflectedintensity of inspection tool light at the reflective regions and thenon-reflective regions, the defect search tool will have difficultyrecognizing the mask patterning and any defects therein.

SUMMARY OF INVENTION

An apparatus comprising a reflective mask having non-reflective andreflective regions, where the reflective regions are reflective of afirst light that has an inspection wavelength and are reflective of asecond light that has a semiconductor processing exposure wavelength.The non-reflective regions are less reflective of the first light andthe second light than the reflective regions in order to create: 1) afirst image with a first contrast that is sufficient to identify defectsin the reflective mask and that is formed by reflecting the first lightoff of the reflective mask; and 2) a second image with a second contrastthat is sufficient to expose photoresist that is coated onto asemiconductor substrate and that is formed by reflecting the secondlight off of the reflective mask.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and notlimitation, in the Figures of the accompanying drawings in which:

FIG. 1a shows a transmission mask.

FIG. 1b shows a reflective mask.

FIGS. 2a through 2 g show a reflective mask processing sequence.

FIG. 3 shows an example of the dependence of reflectivity of a sputteredtarget of Ti as a function of N₂ content.

FIG. 4a shows the dependence of the reflectivity of “as deposited” EUVabsorber structures, as a function of wavelength.

FIG. 4b shows the dependence of the reflectivity of EUV absorberstructures, as a function of wavelength, after a dry buffer layer etch.

FIG. 4c shows the dependence of the reflectivity of EUV absorberstructures, as a function of wavelength, after a dry buffer layer etchfollowed by a wet buffer layer etch.

FIG. 4d shows the dependence of the reflectivity of EUV absorberstructures, as a function of wavelength and as a function of the delaybetween the absorber layer etch and the resist strip during the absorberlayer etch sequence.

DETAILED DESCRIPTION

A reflective mask is described having non-reflective and reflectiveregions. The reflective regions are reflective of light at an inspectionwavelength and a semiconductor processing wavelength and thenon-reflective regions are substantially non-reflective of light at theinspection wavelength and the semiconductor processing wavelength. Thecontrast of reflected light off of the non-reflective and reflectiveregions is greater than 0.210 at either of the two wavelengths.

These and other embodiments of the present invention may be realized inaccordance with the following teachings and it should be evident thatvarious modifications and changes may be made in the following teachingswithout departing from the broader spirit and scope of the invention.The specification and drawings are, accordingly, to be regarded in anillustrative rather than restrictive sense and the invention measuredonly in terms of the claims.

In environments where the operational wavelength spectrum of a defectinspection tool used during the mask manufacturing process has little orno overlap with the operational wavelength spectrum of the exposurelight source employed during the semiconductor device manufacturingprocess, the mask may be designed to operate in both the inspection andthe exposure spectra.

For example, in various embodiments, the mask operates at an EUVwavelength during exposure within a semiconductor manufacturingenvironment while the defect inspection tool (used within the maskmanufacturing process) operates at a DUV wavelength. An approach is todesign a mask that is “operable” at both EUV and DUV wavelengths.

An operable reflective mask exhibits a difference in the intensity ofthe exposure light reflected from the reflective mask regions and theintensity of the exposure light reflected by the non-reflective regionsthat is detectable for inspection purposes and suitable formanufacturing exposure purposes. Note that the non-reflective region 105does not necessarily absorb all of the incident exposure light. Thus,since some light intensity may also reflect off of the non-reflectiveregion 105, the above described difference may also be referred to asthe contrast exhibited in the image reflected from the mask

Referring to FIG. 1b, the contrast is usually expressed as thedifference between the intensity of the light reflected off of thenon-reflective region, I_(non-reflective), and the intensity of thelight reflected off of the reflective region, I_(reflective),represented as percentage of the reflected light from the reflective andnon-reflective regions. That is, as provided in equation 1:

Contrast=(I _(reflective) −I _(non-reflective))/(I _(reflective) +I_(non-reflective))  Eqn. 1

In order to be operable (i.e., “exposable”) for EUV based semiconductormanufacturing, the mask's associated contrast in the EUV spectra shouldbe sufficient to properly expose the photoresist that is coated upon thesemiconductor wafer. For typical resists, such as UV6, an acceptablecontrast range is typically any contrast greater than 0.750 as providedby Equation 1 above.

In order to be operable (i.e., “inspectable”) for DUV based defectinspection tools, the mask's associated contrast at the DUV spectrashould be sufficient for the exposure tool to recognize the patternsformed on the mask. For typical defect inspection tools, such as aKLA-Tencor 353UV, KLA-Tencor 365UVHR, Lasertec 9MD84SR, or AppliedMaterials ARIS-I an acceptable contrast range is typically any contrastrange greater than 0.210 as provided by Equation 1 above. In thefollowing discussion, various embodiments are discussed that are capableof exhibiting contrast ranges much greater than 0.210. However, those ofordinary skill will be able to create from the following teachings otherembodiments having contrasts as low as 0.210.

It is important to note that the resists, inspection tools and rangeslisted above are just examples. Resists or inspection tools, other thanthose listed above, may introduce corresponding contrast rangesdifferent from those just described. However, those of ordinary skillwill be able to take the teachings herein and successfully modify theembodiments discussed below accordingly.

Furthermore, recall from the background that defects in the mask'spatterning may be searched for at multiple instances during the maskmanufacturing process. For example, FIGS. 2a through 2 g show a processflow for the manufacture of an EUV mask that may be used according tothe teachings herein. First, as shown in FIG. 2b, a multi-layerstructure 202 is formed upon a substrate 201. The substrate material maybe, among other materials, silicon, fused silica or ultra low expansion(ULE) glass.

The multilayer structure 202 is designed to reflect EUV light and, asdiscussed in more detail below, corresponds to a reflective mask region.The multilayer structure 202, due to the materials and thickness used ateach layer, creates a series of constructively interfering waves formedby the reflection of EUV exposure light at each layer in the multilayerstructure 202.

A typical multilayer structure 202 may be implemented with 40 pairs ofalternating layers of Molybdenum (Mo) and Silicon (Si) havingapproximate thickness of 2.7 Å and 4.0 Å, respectively. Such a Mo/Simultilayer structure typically has a peak reflection of about 65% at awavelength of 13.4 nm. However, the exact thickness of the layers andthe number of layer pairs may be varied by those of ordinary skill totune the wavelength at which the EUV reflectivity is the highest and therange of the wavelengths where the multilayer is reflective.

Also, other layering structures, such as Mo/Be or MoRu/Be among othersmay be used as well. The multilayer structure 202 is formed by theexecution of a plurality of layering steps, generally known in the art,and are not shown in FIG. 2 for simplicity. Furthermore, the specificthickness of each layer suitable for EUV reflection may also be readilydetermined by those of ordinary skill. Currently, most multilayerstructures 202 have reflectivity within the DUV spectrum between 50 and70%.

As shown in FIG. 2c, after the formation of multilayer structure 202,buffer layer 203 is formed over the multilayer structure 202. Bufferlayer 203 is typically an oxide, such as SiO₂. Buffer layer 203 protectsmultilayer structure 202 during absorber layer 204 etch and correctivere-work of defects found in the masks patterning. The thickness of thebuffer layer 203, as discussed in more detail below, may be used toadjust the contrast of the reflected image off of the mask. Other bufferlayer materials that may be used include SiON.

An absorber layer 204 is then formed over buffer layer 203 as shown inFIG. 2d. Absorber layer 204 is used to absorb semiconductormanufacturing exposure light. Prior art techniques typically employAluminum (Al) as an absorber material. However, as discussed in moredetail ahead, other materials such as Titanium (Ti), Titanium Nitride(TiN), Chrome (Cr) and Nickel Silicide (NiSi) may be used to enhance theinspection contrast associated with the mask. The thickness used for theabsorber layer 204 should be sufficient to absorb enough of the EUVexposure light. After a resist is applied to absorber layer 204 and thenpatterned with a radiation source (e.g., a light source or an e-beamsource). Openings in the resist layer 206 are then created after aresist develop step, exposing the underlying absorber layer 204.

Then absorber layer 204 material is removed (e.g., by a plasma etch)from the openings 205 in the resist layer 206, as shown in FIG. 2e,which exposes the underlying buffer layer 203. The resist layer 206 isthen removed as shown in FIG. 2f. Buffer layer 203 is then removed(e.g., by a dry oxide etch or a combination of dry and wet oxide etch)resulting in a completed mask structure, shown in FIG. 2g. Mask regions207 having an absorber layer 204 correspond to the mask's non-reflectiveregions while mask regions 208 exposing the multilayer structure 202correspond to the mask's reflective regions.

As mentioned above, the defect inspection process may take place at morethan one process step within the mask manufacturing sequence shown inFIGS. 2a-g. For example, in various embodiments, the mask is observedwith an inspection tool for patterning defects after the absorber layer204 is etched and the resist 206 is removed (i.e., after the maskstructure shown in FIG. 2f is formed). Any defects are corrected forwith the buffer layer 203 acting as a protective layer for themultilayer structure 202. Then, as a final “go/no-go” test, the mask'spatterning quality is again observed with an inspection tool after themanufacturing process is completed (i.e., at the mask structure in FIG.2g).

Thus, the structure shown in FIG. 2f should exhibit suitable contrastfor DUV light while the structure shown in FIG. 2g should exhibitsuitable contrast for EUV and DUV light. Various approaches may beundertaken to create a reflective mask that may be used for exposurewithin the EUV spectrum and inspection within the DUV spectrum. In oneapproach, the material(s) used to form the absorber layer 204intrinsically absorb light but do not substantially reflect light inboth spectra. In another approach, an anti-reflective coating (ARC) thatcancels reflected light within the DUV spectrum is formed as part of theabsorber layer 204 structure.

In embodiments directed to an absorber layer 204 having material(s) thatintrinsically absorb and do not substantially reflect in both the EUVand DUV spectra, the focus is typically on materials that absorb and donot substantially reflect at the DUV spectra. That is, most conductingmaterials tend to intrinsically absorb EUV light but are reflective ofDUV light. Optical properties of various materials may be found inpublished references such as: 1) Handbook of Optical Constants ofSolids, vol. I, 185, and vol. II, 1991, edited by E. D. Palik, (AcademicPress, Inc. 1991); and 2) J. H. Wever and H. P. R. Frederikse, Opticalproperties of metals and semiconductors, CRC Handbook of Chemistry andPhysics, 66th edition, edited by R. C. Weast, M. J. Astle, and W. H.Beyer, (CRC Press, Boca Raton, Fla., 1985).

Both Ti and TiN have been found to exhibit absorbing and substantiallynon-reflective properties within the DUV spectrum. Deposition processingruns have indicated that low deposition power within the depositionchamber form substantially non-reflective Ti or TiN films (i.e. filmswith reflectivity at or under 35%). FIG. 3 shows the reflectivity at theindicated wavelengths that were observed as N₂ content was varied as apercentage against Ar content (i.e., Ar content+N₂ content=100%).Generally, N₂ fractions below 0.50 correspond to Ti and N₂ fractionsabove 0.50 correspond to TiN. The TiN films of FIG. 3 exhibit areflectivity of 28-32% in the DUV spectrum. Note that in the processexercise of FIG. 3, TiN reflectivity was minimal at a Ar:N₂ ratio of1:1.

The exercise of FIG. 3 was performed with a Ti target, 4 mTorr of totalAr and N₂ gas pressure at 6.5 kW of power. Even better reflectivity(e.g., 23-28% for TiN) was obtained when the power was reduced to 3.0 kWwhich indicates that a low power (i.e., below 6.5 kW) deposition canform films that are acceptably absorptive and substantiallynon-reflective within the DUV spectrum. A 23% reflectivity correspondsto a contrast of 0.505 for a multilayer structure 202 that is 70%reflective in the DUV spectrum. Note that other experimental data andthe above described published references also indicate that NiSi, Cr andZr possess optical properties suitable for forming EUV mask absorberlayers with substantially low reflectivity within the DUV spectrum.

Along with using materials such as Ti, TiN, NiSi, Cr or Zr thatintrinsically absorb but do not substantially reflect light within theDUV spectrum, additional processing steps may be undertaken to evenfurther improve (i.e., reduce) their reflectivity within the DUVspectrum. For example, the surface of the absorber layer 204 may beroughened in order to “scatter” reflected DUV light (from the absorberlayer 204) away from the collection lens of the inspection tool.

The surface roughening step may be applied at any suitable instance inthe mask manufacturing sequence such as before buffer layer 203 removal,during buffer layer 203 removal or after buffer layer 203 removal. FIG.4a shows a typical example of the reflectivity observed for Ti absorberlayers 204 as deposited (i.e., not exposed to surface roughening (alsoreferred to as “treatment”)) and serves as a benchmark for comparisonwith treated absorber layers.

FIGS. 4b and 4 c show that absorber layers 204 having reflectiveproperties as shown in FIG. 4a may demonstrate reduced reflectivity ifexposed to surface treatments such as those described below. Note theindicated delay periods 401 correspond to the delay between the absorberlayer etch and resist strip during the absorber layer 204 etch sequence.In the processes used to generate the data of FIGS. 4b and 4 c, theabsorber layer 204 surface was roughened simultaneously with the etch ofthe buffer layer 203. In FIG. 4b, a completely dry buffer layer etch wasused; while in FIG. 4c, a partial oxide removal using a dry buffer layeretch followed by a wet buffer layer etch was used.

In FIG. 4b, as mentioned above, the buffer layer 203 was removedentirely with a dry etch. The dry etch was performed at 40 mTorr, with a100 sccm flow of CHF₃ and 10 sccm flow of O₂. Note that reflectivitiesat or below 2.5% in the DUV spectrum have been obtained. Thiscorresponds to contrasts at or greater than 0.931 for multilayerstructures 202 having a reflectivity of 70% in the DUV spectrum.

In FIG. 4c, the buffer layer 203 was partially removed (approximately75% of its original thickness) with a dry etch before being removed witha wet etch. The dry etch was performed with the same process parametersas described above (but for a shorter time period). The wet etch wasperformed by an etch in a dilute solution of hydrogen fluoride inethylene glycol. Observed surface roughness was between 9.0 and 13.0 Å

Referring back to FIG. 2, recall that the structure shown in FIG. 2fshould exhibit suitable contrast for DUV light while the structure shownin FIG. 2g should exhibit suitable contrast for EUV and DUV light.Various approaches may be undertaken to create a reflective mask thatoperates not only within the EUV spectrum but also the DUV spectrum. Inone approach, just described, the material(s) used to form the absorberlayer 204 inherently absorb but do not substantially reflect (i.e., havea reflectivity at or below 35%) light in both spectra.

In another approach, however, an anti-reflective coating (ARC) thatcancels reflected light within the DUV spectrum is formed as part of theabsorber layer 204 structure. Such structures may be referred to as ARCabsorber embodiments. As is known in the art, ARC layers are typicallyformed according to λ/4n_(i) where λ is the inspection tool's wavelengthand n_(i) is the refractive index of the ARC coating.

This causes light reflected at the air/ARC interface to cancel lightreflected at the ARC/underlayer interface. However, it is important tonote that the actual thickness of the ARC layer may vary if the ARCmaterial demonstrates absorptive properties. That is, ARC layers aredesigned to produce reflected waves (180 degrees out of phase) havingequal amplitudes. The amplitude of the reflected waves is a function ofthe absorptive nature of the ARC material which ultimately will affectthe proper thickness to be used. Those of ordinary skill can adjust thethickness of their ARC layers accordingly.

In some ARC absorber embodiments, the absorber layer 204 is a TiN/Tistructure where the TiN acts as the ARC layer and is applied to thesurface of the underlying Ti. In one embodiment (for a 257 nm inspectionwavelength), the TiN is 8.0 nm and the Ti layer is 15.0 nm, althoughthose of ordinary skill can readily determine a proper ARC andunderlayer thickness for a given mask and inspection wavelength. Inother 257 nm ARC absorber embodiments, a TiN/Al multilayer structure maybe formed such as a 14.0 nm TiN ARC applied to an underlying 60.0 nm Allayer. In yet another other embodiments, CrO_(x)/Cr structures may beformed.

In yet another ARC absorber embodiment, an oxide layer is allowed toform on top of the absorber layer 204. Ti absorber layers 204 have beenfound to oxidize. Cr also oxidizes. These oxide layers may be used as anARC if the thickness of the oxide is proper. Furthermore, it has alsobeen observed that the amount of time the resist layer 206 remains onthe absorber layer 204, after the absorber layer etch (FIG. 2e) andbefore the resist layer 206 is removed (FIG. 2f) affects the thicknessof the oxide formed on the absorber layer.

That is, the amount of time that elapses between the steps shown in FIG.2e and 2 f affect the thickness of the oxide found on the absorber layer204. FIG. 4d shows the variation in reflectivity for the Ti absorbers ofFIGS. 4b and 4 c before the aforementioned surface roughening treatmentswere performed. Delay periods 401 correspond to the delay between theabsorber layer etch and resist strip during the absorber layer etchsequence. Note that in this example, a delay of 24 hours was optimal.Also note that, referring back to FIGS. 4b and 4 c, the oxide layer wasdestroyed by the surface roughening treatment which accounts for thelack of sample variance as a function of resist removal delay time.

In order to further enhance the mask's contrast during mask inspectionafter resist removal (FIG. 2f), for any approaches described above, thebuffer layer 203 thickness may be tailored to create constructiveinterference above the multilayer structure 202. That is, contrast isimproved as the multilayer structure 202 becomes more reflective withtailored buffer layer 203 over multilayer structure 202. Here, in orderto create constructive interference, the buffer layer thickness shouldcorrespond to approximately λ/2n_(i) where λ is the inspection tool'swavelength and n_(i) is the refractive index of the buffer layer 203.However, similar to the discussion above relating to the ARC layer; theexact proper thickness is a function of the absorptive nature of thebuffer layer 203. Again, those of ordinary skill will be able to tailortheir buffer layer 203 thickness accordingly. Alternatively, a materialreflective of light at the inspection wavelength may be used for bufferlayer 203. For example, Aluminum has greater than 90% reflectivity inthe DUV spectrum.

So far, the above discussion has been directed to masks having absorber204 layers that are absorptive within the EUV and DUV spectrum andmultilayer structures 202 that are reflective within the EUV and DUVspectrum. However, in yet another mask approach, the absorber material204 may be designed to absorb light within the EUV spectrum and reflectlight in the DUV spectrum. In this same approach, the buffer layer 203my be tailored to act as an ARC layer (in the DUV spectrum) over themultilayer structure 209 such that, referring to FIG. 2f, high contrastis obtained in reverse polarity.

That is, the absorber layer 204 reflects defect inspection tool DUVlight and absorbs EUV exposure light while the buffer layer 203 does notappreciably reflect the inspection tool DUV light. Approaches such asthis may be used with more traditional absorber materials, such as Al,that exhibit high reflectivity of DUV light.

What is claimed is:
 1. An apparatus, comprising: a reflective maskhaving non-reflective and reflective regions, said reflective regionsreflective of light at an inspection wavelength and a semiconductorprocessing wavelength, said non-reflective regions being less reflectiveof said first light and said second light than said reflective regionsin order to create: 1) a first image with a contrast greater than 0.210and that is formed by reflecting said first light off of said reflectivemask; and 2) a second image with a contrast greater than 0.750 and thatis formed by reflecting said second light off of said reflective mask.2. The apparatus of claim 1 wherein said semiconductor processingwavelength is within the EUV spectrum and said inspection wavelength iswithin the DUV spectrum.
 3. The apparatus of claim 1 wherein saidnon-reflective regions comprise a material that absorbs EUV light and issubstantially non-reflective of DUV light.
 4. The apparatus of claim 3wherein said material is Ti.
 5. The apparatus of claim 3 wherein saidmaterial is TiN.
 6. The apparatus of claim 3 where said material isNiSi.
 7. The apparatus of claim 3 where said material is Cr.
 8. Theapparatus of claim 3 where said material is Zr.
 9. The apparatus ofclaim 1 wherein said non-reflective regions comprise a roughenedsurface.
 10. The apparatus of claim 1 wherein said non-reflectiveregions comprise an ARC layer.
 11. The apparatus of claim 10 whereinsaid non-reflective regions comprise TiN over Ti, where said TiN is saidARC layer.
 12. The apparatus of claim 10 wherein said ARC layer is anoxide.
 13. An apparatus, comprising: a semiconductor substratemanufacturing tool having a reflective mask positioned along an opticalpath between an exposure light source and a semiconductor substrate,said reflective mask having non-reflective and reflective regions, saidreflective regions reflective of light at an inspection wavelength and asemiconductor processing wavelength, said non-reflective regions beingless reflective of said first light and said second light than saidreflective regions in order to create: 1) a first image with a contrastis greater than 0.210 and that is formed by reflecting said first lightoff of said reflective mask; and 2) a second image with a contrast thatis greater than 0.750 and that is formed by reflecting said second lightoff of said reflective mask.
 14. The apparatus of claim 13 wherein ofsaid semiconductor processing wavelength is within the EUV spectrum andsaid inspection wavelength is within the DUV spectrum.
 15. The apparatusof claim 13 wherein said non-reflective regions comprise a material thatabsorbs EUV light and is substantially non-reflective of DUV light. 16.The apparatus of claim 15 wherein said material is Ti.
 17. The apparatusof claim 15 wherein said material is TiN.
 18. The apparatus of claim 15where said material is NiSi.
 19. The apparatus of claim 15 where saidmaterial is Cr.
 20. The apparatus of claim 15 where said material is Zr.21. The apparatus of claim 13 wherein said non-reflective regionscomprise a roughened surface.
 22. The apparatus of claim 13 wherein saidnon-reflective regions comprise an ARC layer.
 23. The apparatus of claim22 wherein said non-reflective regions comprise TiN over Ti, where saidTiN is said ARC layer.
 24. The apparatus of claim 22 wherein said ARClayer is an oxide.
 25. An apparatus, comprising: a reflective maskhaving non-reflective and reflective regions, said reflective regionsbeing reflective of a first light that has an inspection wavelength andbeing reflective of a second light that has a semiconductor processingexposure wavelength, said non-reflective regions being less reflectiveof said first light and said second light than said reflective regionsin order to create: 1) a first image with a first contrast that issufficient to identify defects in said reflective mask and that isformed by reflecting said first light off of said reflective mask; and2) a second image with a second contrast that is sufficient to exposephotoresist that is coated onto a semiconductor substrate and that isformed by reflecting said second light off of said reflective mask. 26.The apparatus of claim 25 wherein said semiconductor processing exposurewavelength is within the EUV spectrum and said inspection wavelength iswithin the DUV spectrum.
 27. The apparatus of claim 25 wherein saidnon-flective regions further comprise a material that absorbs EUV light.28. The apparatus of claim 27 wherein said material further comprisesTi.
 29. The apparatus of claim 28 wherein said material furthercomprises TiN.
 30. The apparatus of claim 27 where said material furthercomprises NiSi.
 31. The apparatus of claim 27 where said materialfurther comprises Cr.
 32. The apparatus of claim 27 where said materialfurther comprises Zr.
 33. The apparatus of claim 25 wherein saidnon-reflective regions further comprise a roughened surface.
 34. Theapparatus of claim 25 wherein said non-reflective regions furthercomprise an ARC layer.
 35. The apparatus of claim 34 wherein saidnon-reflective regions further comprise TiN over Ti, where said TiN issaid ARC layer.
 36. The apparatus of claim 34 wherein said ARC layerfurther comprises an oxide.
 37. An apparatus, comprising: asemiconductor substrate exposure tool having a reflective maskpositioned along an optical path between an exposure light source and asemiconductor substrate, said reflective mask having non-reflective andreflective regions, said reflective regions being reflective of a firstlight that has an inspection wavelength and being reflective of a secondlight that is produced by said exposure light source and that has asemiconductor processing exposure wavelength, said non-reflectiveregions being less reflective of said first light and said second lightthan said reflective regions in order to create: 1) a first image with afirst contrast that is sufficient to identify defects in said reflectivemask and that is formed by reflecting said first light off of saidreflective mask; and 2) a second image with a second contrast that issufficient to expose photoresist that has been coated onto saidsemiconductor substrate and that is formed by reflecting said secondlight off of said reflective mask.
 38. The apparatus of claim 37 whereinsaid semiconductor processing wavelength is within the EUV spectrum andsaid inspection wavelength is within the DUV spectrum.
 39. The apparatusof claim 37 wherein said non-reflective regions further comprise amaterial that absorbs EUV light.
 40. The apparatus of claim 39 whereinsaid material further comprises Ti.
 41. The apparatus of claim 40wherein said material further comprises TiN.
 42. The apparatus of claim39 where said material further comprises NiSi.
 43. The apparatus ofclaim 39 where said material further comprises Cr.
 44. The apparatus ofclaim 39 where said material further comprises Zr.
 45. The apparatus ofclaim 37 wherein said non-reflective regions further comprise aroughened surface.
 46. The apparatus of claim 37 wherein saidnon-reflective regions further comprise an ARC layer.
 47. The apparatusof claim 46 wherein said non-reflective regions further comprise TiNover Ti, where said TiN is said ARC layer.
 48. The apparatus of claim 46wherein said ARC layer further comprises an oxide.